Problem: Tiffany ate 4 slices of cake. Gabriela ate 2 slices. If Tiffany ate $\dfrac{4}{8}$ of the cake, what fraction of the cake is remaining?
Explanation: If 4 slices represent $\dfrac{4}{8}$ of the cake, there must have been a total of 8 slices. $\text{fraction of cake remaining} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 6 slices, which leaves 2 out of 8 slices remaining. There is $\dfrac{2}{8}$ of the cake remaining.